Analog-to-digital (A/D) and digital-to-analog (D/A) converters are broadly used in electronic systems, such as electronic control loops, and their performance in terms of space and efficiency are very challenging.
For example, instead of performing analog processing operations, often electronic systems perform digital processing operations.
For example, FIG. 1 shows an exemplary electronic system that includes an analog-to-digital converter 10 configured to generate digital samples DS_OUT of an analog input signal, such as an input voltage VIN. A digital processing unit 12 is configured to generate a digital signal DS_IN as a function of the digital samples DS_OUT of the analog input signal and a digital-to-analog converter 14 is configured to generate an analog output signal, such as an output voltage VOUT, as a function of the digital signal DS_IN.
For example, the digital processing circuit 12 may be a dedicated hardware circuit, a micro-processor programmed via software instructions, a programmable logic circuit, such as a Field Programmable Gate Array (FPGA), or any combination thereof. Moreover, often the A/D converter 10, the digital processing unit 12 and the D/A converter 14 are integrated in a single integrated circuit, such as a micro-controller.
Traditionally, A/D and D/A converters are two separated circuits of the electronic system. Various types of A/D and D/A converters are known in the art. For example, one kind of A/D converters is based on a time-to-digital converter (TDC). Such TDCs use internal propagation delays of signals through gates to measure time intervals with very high precision. For example, such a TDC may be used to measure the time required to charge a reference capacitor to a given threshold value via the analog input signal.